1. Field of the Invention
The present invention relates to a variable movement headrest arrangement for providing support to the head of an occupant of a vehicle upon vehicle impact.
2. Background Art
Improvements in safety mechanisms in the automotive industry continue to be made year after year. Such safety mechanisms include safety headrests. Example safety seat headrests can be found in Viano et al., U.S. Pat. No. 5,378,043, which is incorporated herein by reference. Such safety headrest mechanisms provide support to the head of a vehicle occupant during crash situations.
More specifically, upon rear impact of a vehicle, the occupant of the vehicle compresses into the vehicle seatback, as the head, neck, and torso move substantially in unison. There typically is greater compression in the torso and buttocks regions than in the shoulder region of the occupant. Thus, it has been a concern that the seatback may possibly deflect under the torso and buttocks load before the head and neck of the occupant contacts the headrest attached to the seatback.
Upon front impact of a vehicle, an occupant of the vehicle moves forward relative to the vehicle seatback. Upon contact with a front interior panel or a deployed air bag from the front panel, the occupant experiences rebound movement in a rearward direction. Similar to a rear impact situation as described above, the occupant in such a situation would then provide a rearward load into the seatback and compress into the vehicle seatback, as the head, neck, torso, and buttocks move substantially in unison. Thus, in a front impact it is also a concern that the seatback may possibly deflect under the torso load prior to the head and neck of the occupant contacting the headrest.
As a result, safety headrest mechanisms have been designed such that, upon rear impact, the occupant""s torso contacts an impact target of a vehicle seat with a rearward load or force. The impact target is operatively connected to a headrest cushion portion such that, upon the rearward load on the impact target, the headrest cushion portion moves forwardly toward the head of the occupant. The forward movement of the cushion portion in the crash situation lessens the gap which may exist between the head of the occupant and the headrest cushion portion, preventing or decreasing the risk of whiplash to the occupant.
However, it would be desirable to have the headrest arrangement move forward at a higher velocity to decrease the gap more quickly, but without contacting the occupant""s head while moving at the higher velocity.
It is an object of the present invention to provide a cost effective mechanism to support the head of an occupant of a vehicle upon vehicle impact.
In carrying out the above object, and other objects and features of the invention, a new method of providing head support with a movable headrest of a vehicle seat to a vehicle occupant head during impact of the vehicle is provided. The method comprises moving the headrest toward the head of the occupant in a first manner upon impact of the vehicle, and moving the headrest toward the head of the occupant in a second manner different from the first manner.
In a more specific embodiment, the first manner in which the headrest is moved has a first forward velocity and the second manner in which the headrest is moved has a second forward velocity different from the first velocity. The first forward velocity may be greater than the second forward velocity.
In another more specific embodiment, the first manner in which the headrest is moved is along a first trajectory of the headrest and the second manner in which the headrest is moved is along a second trajectory of the headrest different from the first trajectory. The second trajectory may be more upwardly than the first trajectory.
In another more specific embodiment, moving the headrest in the first manner employs an instant center axis which is lower than the instant center axis employed when moving the headrest in the second manner.
In another more specific embodiment, the method further comprises contacting the head of the occupant with the headrest during the second manner of moving the headrest.
In another more specific embodiment, the method further comprises reducing the forward velocity of the headrest prior to contact of the headrest with the head of the occupant.
In another more specific embodiment, the first manner in which the headrest is moved is a first arcuate path and the second manner in which the headrest is moved is a second arcuate path different from the first arcuate path. The headrest may move more forwardly along the first arcuate path than along the second arcuate path toward the head of the occupant. The headrest may move more upwardly along the second arcuate path than along the first arcuate path relative to the head of the occupant.
In another more specific embodiment, the first manner in which the headrest is moved has a first forward velocity and a first trajectory and the second manner in which the headrest is moved has a second forward velocity and a second trajectory and at least one of the first forward velocity and trajectory is different from the second forward velocity and trajectory respectively. The first forward velocity and trajectory may be different than the second forward velocity and trajectory respectively.
The method of providing head support with a movable headrest of a vehicle seat to a vehicle occupant head during impact of the vehicle may also comprise moving the headrest toward the head of the occupant at a first velocity upon impact of the vehicle, and moving the headrest toward the head of the occupant at a second velocity before the head of the occupant makes contact with the headrest, the first velocity being greater than the second velocity.
In another more specific embodiment, the method further comprises reducing movement of the headrest after movement of a predetermined distance and before the headrest contacts the head of the occupant to provide support.
The method of providing head support with a movable headrest of a vehicle seat to a vehicle occupant head during impact of the vehicle may also comprise moving the headrest toward the head of the occupant along a first trajectory and at a first forward velocity upon impact of the vehicle, and moving the headrest toward the head of the occupant along a second trajectory and at a second forward velocity before the head of the occupant contacts the headrest, one of the first trajectory and first forward velocity being different from one of the second trajectory and second forward velocity respectively. The first trajectory and first forward velocity may be different than the second trajectory and second forward velocity respectively. The method may also further comprise reducing movement of the headrest after movement of a predetermined distance and before the headrest contacts the head of the occupant to provide support.